The present invention relates to magnetic chucks and more particularly to a method of fabricating an interlock top plate assembly for such a chuck.
Electrically energized magnetic chucks are frequently used for holding iron or steel work pieces during machining operations. One popular type of chuck is a so-called interlock chuck in which a plurality of magnetic fingers extend from different portions of a coil core and the fingers of different polarity are interlaced so as to provide a convoluted or highly distributed magnetic gap appropriate for holding parts of different sizes, shapes and thicknesses.
Various techniques have been employed for making the magnetic finger units employed in these chucks. In one prior art construction, magnetic fingers having a flowing or curved shape have been flame cut from flat stock and assembled with spacers. In another construction, described in German Pat. No. 1,147,459, a solid plate is flame cut in a zigzag pattern with the angle of the cutting head being varied so as to provide an inclined gap, the inclination of the gap being such that the gap is highly convoluted on the top surface and at the bottom surface of the plate essentially follows the usual, essentially straight gap in the coil form. Other complex pole piece configurations have been constructed by casting the shapes using conventional foundry techniques, e.g. sand casting.
Among the several objects of the present invention may be noted the provision of a method for relatively easily fabricating top plate assemblies for interlock magnetic chucks; the provision of such a method which utilizes readily available, stock materials; the provision of such a method which yields a pole piece assembly of highly desirable magnetic properties; and the provision of such a method which is relatively simple and inexpensive. Other objects and features will be in part apparent and in part pointed out hereinafter.